<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<meta name="viewport" content="width=device-width, initial-scale=1.0">
	<title>Document</title>
	<style>
		.font-change {
			font-size: 20px;
			/* font-size: 120%; */
			/* font-size: .75em; */
		}
	</style>
</head>
<body>
	<p class="font-default">default font 默认字体</p>
	<p class="font-change">font family change font 字体系列改变字体</p>
</body>
</html>